In the piece, published by Fairfax in June, Sharma asserted that teachers work “hours closer to three-quarters of a regular full-time job”.

Sharma issued an apology yesterday, following widespread criticism.

In response, the NSW Teachers Federation slammed the apology.

"Your comments denigrating teachers were no mere off-the-cuff remark. They were considered and written in an op-ed in a major newspaper. You didn’t apologise then, but now that those comments have caused you serious embarrassment, you offer a self-serving apology," the organisation wrote.

Among those to criticise Sharma's opinion piece was Wentworth ALP candidate Tim Murray, who wrote that teachers “continue to work hard into the night, preparing lessons, marking, assessing etc.”

Greens Senator Mehreen Faruqi and political commentator Mike Carlton added their voices to the furore, with Carlton labelling Sharma’s comment “a gross insult”.

More broadly, Sharma’s piece argued that the school day is too short and that school facilities are underutilised during the holidays, and that this puts unnecessary pressure on parents.

The story was published not long after Coalition backbencher Andrew Laming weighed in on the issue, arguing that teachers should work eight hours a day and get just four weeks annual leave.

Laming said that the work teachers do at home is “completely unquantified, invisible time”.

“There is just no evidence that the work they are doing at home makes any difference, and there’s no evidence that what they do at home is actually where you’d want a teacher focusing their efforts," he said.

Polls will open in Wentworth on October 20.